825221 has 4 divisors (see below), whose sum is σ = 829344. Its totient is φ = 821100.

The previous prime is 825203. The next prime is 825229. The reversal of 825221 is 122528.

825221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 825221 - 2¹⁴ = 808837 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 825193 and 825202.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 825221.

It is not an unprimeable number, because it can be changed into a prime (825229) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1745 + ... + 2166.

It is an arithmetic number, because the mean of its divisors is an integer number (207336).

2⁸²⁵²²¹ is an apocalyptic number.

It is an amenable number.

825221 is a deficient number, since it is larger than the sum of its proper divisors (4123).

825221 is a wasteful number, since it uses less digits than its factorization.

825221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4122.

The product of its digits is 320, while the sum is 20.

The square root of 825221 is about 908.4167545791. The cubic root of 825221 is about 93.7972467038.

Adding to 825221 its reverse (122528), we get a palindrome (947749).

The spelling of 825221 in words is "eight hundred twenty-five thousand, two hundred twenty-one".